A Fully Integrated, Flexible and Tunable Capacitive Strain Sensor Based on Magneto-Dielectric for Human Motion Monitoring

Flexible strain sensors for monitoring human motion require a wide working range and high sensitivity. Here, we present a mechanically flexible and fully integrated capacitive strain sensor designed for human motion monitoring. The device’s enhanced sensitivity and wide operational range are achieved using a magneto-dielectric layer (MDL) composed of magnetic nanoparticles embedded in polydimethylsiloxane (PDMS). These nanoparticles dynamically realign in response to strain stimuli, significantly amplifying the capacitance change. The sensor exhibits a sensitivity four times greater than comparable devices using PDMS alone as the dielectric layer. Additionally, it demonstrates a wide working range (20000 µm – 6000 µm), high linearity (0.99), and rapid detection time (0.2 s). By bridging the gap between the capacitive sensing, conditioning, processing and data transmission, the presented work integrates flexible sensor with integrated silicon chips on flexible substrate, offering a complete solution for monitoring human motion.